Phlebotomy tubes and phlebotomy tube holders for coupling thereto phlebotomy tubes used to collect a patient's blood sample are well known. Some such phlebotomy tubes and phlebotomy tube holders are described in U.S. Pat. Nos. 5,086,780, by Schmitt, 5,104,705, by Quackenbush, 5,165,419, by Sarstedt, and 5,399,318, by Mancilla et al. However, known drawing tubes (some having an anticoagulant composition, blood preservative, or the like stored therein) and phlebotomy tube holders are typically made of clear glass and/or plastic for enabling a phlebotomist technician to visual inspect the blood sample level collected and stored therein. During the drawing of the blood sample, it is critical that the phlebotomist technician can visually inspect the blood sample level to ensure that the minimum required amount of blood is obtained and that the blood is not overdrawn.
Some blood tests, such as, without limitation, vitamin deficiency tests, require that the blood sample not be exposed to light. Presently, for such blood tests, the technicians must immediately wrap the phlebotomy tube in aluminum foil or other material for preventing the blood sample from prolonged exposure to the light which is cumbersome and awkward. Nevertheless, such practices are often futile since even the slightest exposure to light can provide inaccurate blood test readings. Therefore, the blood sample must be discarded and redrawn.
It can be readily seen that there exists the continuing need for a non-light penetrating phlebotomy tube for protecting collected blood stored therein from light exposure; and, a non-light penetrating phlebotomy tube having a temperature sensitive level indicator for indicating to the phlebotomist technician the level of blood sample being collected thereby preventing overdrawing and underdrawing of the patient's blood.